Attention: Harmonic balancer (crank pulley) [Archive]

91NSX#60

29-07-2010, 01:44 PM

I've posted this on prime as well, but I feel this issue need's to be spread around as widely as possible.

I had read a few posts on prime during last winter about the HB, so I decided to order one for my own car just in case, that one didnt show up before the season started so I inspected my old one and found no signs of "weakness". No tears in the rubber or anyhing loose.
Anyway, about a month later, it came apart and strated to chew into my timing belt cover, resulting in pieces of the cover being thrown onto the timing belt.

How the TB cover looked like after:
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/SNC00112.jpg
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/SNC00114.jpg

The harmonic balancer (crank pulley):
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/hb.jpg

The piece of TB cover with obvious marks of TB teeth:
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/SNC00116.jpg

91NSX#60

29-07-2010, 01:44 PM

So I changed the TB and waterpump and so on, checking the timing as I went along. The aft intake and exhaust cams was 2 teeth off both, but I hoped the valves was ok still.

I installed primemember "Titaniumdave"'s shield and a brand new pulley.
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/SNC00130.jpg
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/SNC00131.jpg

But at the compression test before startup there was no compression in the aft cylinders at all, so there was nothing else to do than pull the heads off.
This is what i found:
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/IMG_6431s.jpg
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/IMG_6433s.jpg

So to all of you fellow NSX owners out there, get that shield installed. Its a really cheap insurance for a engine failure. And its installed in less than 2 hours for even the most inexperienced.

Nick Graves

29-07-2010, 07:56 PM

I feel sick.

New pulley at next service, I think.

vtecdirect

29-07-2010, 08:38 PM

shall I order in a bunch of pulleys then?

29-07-2010, 08:41 PM

Wow I feel for you mate that is bad news. How many miles on her at the time? I got mine on the shelf and I think I will give it a go tomorrow since I also have the hex tool!

Sudesh

29-07-2010, 10:21 PM

shall I order in a bunch of pulleys then?

Any word on mine!

Sudesh

29-07-2010, 10:23 PM

Wow I feel for you mate that is bad news. How many miles on her at the time? I got mine on the shelf and I think I will give it a go tomorrow since I also have the hex tool!

I replaced the pulley on Andrews car and added the shield for him also. Dont think the shield is necessary on a new pulley and I would consider changing the pulley at every TB service anyway.

91NSX#60

29-07-2010, 10:42 PM

Wow I feel for you mate that is bad news. How many miles on her at the time? I got mine on the shelf and I think I will give it a go tomorrow since I also have the hex tool!

She has 152k KM on the clock, about 95k miles.

In the end it's just a good excuse to get some go fast goodies in there :D

Hagasan

29-07-2010, 10:46 PM

Any word on mine!

I was speaking with Kaz at Silverstone and he said that the pulleys were out of stock even in Japan at the moment...

29-07-2010, 11:11 PM

It took me about 4 months for mine IIRC. I wanted it done with the TB but honda could not get it on time. Incidentaly the master tech told me that he had only seen one go on a car that had been stolen and overrevved.

Eitherway I am glad I got a spare engine!

Sudesh

29-07-2010, 11:15 PM

4 MONTHS!! Hope mine isnt going to be that long. I think Andrews arrived in 3 or 4 weeks? Cant remember now but I'm sure he can let us know.

Senninha

30-07-2010, 06:58 AM

Prevention is better (and usually cheaper) than the cure.

Mine is on route and will be installed shortly, current one inspected and looks fine but its one less thing to worry about.

I tend to agree with Sudesh and will probably swap with the TB etc.

regards,

markc

30-07-2010, 07:42 AM

I was speaking with Kaz at Silverstone and he said that the pulleys were out of stock even in Japan at the moment...

Sounds like the usually British disease of panic buying. I wonder how many people now have one "on the shelf" ready to be installed at the next service?

Sure these things fail and can do significant damage in some cases when they do but its not worth having one on the shelf if you're not going to fit it very soon.

I guess Honda (UK) made a rod for the their own back by not specifying a definite replacement period so, due to even the youngest cars being 5yrs old, we now have a situation where all UK NSX owners potentially want to have their pulleys changed hence no stock.

Cheers

Mark

Sudesh

30-07-2010, 08:56 AM

Totally agree with you, no point in leaving it sitting there until the next service, waiting for the next service may be too late!

Its also a fairly easy item to exchange with the correct tools so I wouldnt be waiting either. As soon as mine arrives I'll be installing it along with new ancillary belts.

Sounds like the usually British disease of panic buying. I wonder how many people now have one "on the shelf" ready to be installed at the next service?

Sure these things fail and can do significant damage in some cases when they do but its not worth having one on the shelf if you're not going to fit it very soon.

Cheers

Mark

NSXGB

30-07-2010, 09:06 AM

Bit like Ground Hog Day reading this post! I remember the panic when Martin's went a while back, everybody panicing and saying they were going to order a new pulley and or shield. . . Did nobody do it?!
Kaz has also taken the time to write on this in his health check thread. Maybe his work could be promoted to a more prominent place on the board in his own section maybe ?

Anyway, I do actually have a pulley 'in stock' if anyone needs it. . . £500 :)

Nick Graves

30-07-2010, 09:55 AM

Now I know the symptoms, waiting 'til the next service seems sensible. The car's a decade old now.

Like Ford Prefect, I'd not really done my research & had assumed the problem was the same as the Prelude; ie unscrewing itself and therefore not as destructive as this. That was a stupid assumption, given the C32 rotates the right way and an H22 doesn't.

nobby

30-07-2010, 11:30 AM

THINK YOU SHOULD MATE!

Thank goodness I purchased mine off you

shall I order in a bunch of pulleys then?

nobby

30-07-2010, 11:41 AM

Mine was about 4 weeks lead time from Andy @ vtec direct. I believe myself and Alf Tupper on here received them around the same time.

jeez not good if looking at 4mths now! :eek: :(

4 MONTHS!! Hope mine isnt going to be that long. I think Andrews arrived in 3 or 4 weeks? Cant remember now but I'm sure he can let us know.

jaffaz32

30-07-2010, 11:45 AM

ATI now do a pulley for the NSX.

This is a Harmonic pulley like factory but lighter.

Might be worth organising a group buy perhaps?

I would be interested in one.

nobby

30-07-2010, 11:48 AM

on inspection of mine; and Sudesh can vouch for this (as he knows better than me), there was no visible signs of wear and tear on the original CP taken off my car. the car has done 49000 miles and the CP was in reasonable nick. no sign of real wear anywhere and was pretty much even all round.

so maybe does not constitute a panic buy, but when you see this post, its hard not to have the thought in your mind.

as Sudesh states I have the guard installed as well, how useful this is if you decide to change CP at each TB service remains to be seen, but its there, and peace of mind for me anyways

hope you all get your replacements in a reasonable time frame. if someones is in really bad condition and they want one that should tide them over, give me a shout happy to pass mine on, all you do is pay for p&p. dont know how feasible this is, but the offer is there

ok

Mine was about 4 weeks lead time from Andy @ vtec direct. I believe myself and Alf Tupper on here received them around the same time.

jeez not good if looking at 4mths now! :eek: :(

Alf Tupper

30-07-2010, 01:20 PM

I have a 1995 car with 49k miles. Soon after buying/collecting it, I went for Kaz's Healthcheck which found that the crank pulley was showing signs of splitting (thanks Kaz).

Ordered pulley from vtec direct, very reasonable price compared with HUK, arrived in 3 weeks (thanks Andy).

I had Thames Ditton Honda fit the pulley and carry out a few other jobs besides. They were one of the original NSX dealers and had no objections to fitting customer supplied parts.

All the above contacts were found/recommended on this forum, so many thanks NSXCB!

91NSX#60

30-07-2010, 06:18 PM

Just to let you all know, I inspected mine just a month (100-200 miles) before it failed, and it showed no signs of deterioration on the rubber part. Mine split where the rubber attaches to the metal part.

http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/IMG_6435s.jpg
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/IMG_6437s.jpg
http://i187.photobucket.com/albums/x178/arjakobs/My%20NSX/IMG_6439s.jpg

Nick Graves

31-07-2010, 11:32 AM

Stuck a finger in mine - well recessed & very clean, which ought to slow deterioration. Rubber doesn't like oil.

31-07-2010, 09:18 PM

Well tomorrow is the day when mine is coming off. Plan is to wake up early and get it done before the F1!

NSXGB

31-07-2010, 09:52 PM

Remember to grease the pulley bolt before reassembly.

gcon45

31-07-2010, 10:09 PM

Well tomorrow is the day when mine is coming off. Plan is to wake up early and get it done before the F1!

All good intentions Ary!

I intend to get up early tomorrow and give the under-side a bit of a detail before the F1 starts.

Never gonna happen!

01-08-2010, 05:31 AM

Well wish me luck LOL!

Silver Surfer

01-08-2010, 08:53 AM

Well wish me luck LOL!

3 hours and counting...;)

SS

01-08-2010, 07:54 PM

All good intentions Ary!

LOL You were right to a point. It had rained last night and one of the other cars car needed a good wax. So by noon time I was finished with that and finished! On to the F1 and that was it!

macrylinda

08-08-2010, 02:13 AM

shall I order in a bunch of pulleys then?
Wow I feel for you mate that is bad news. How many miles on her at the time? I got mine on the shelf and I think I will give it a go tomorrow since I also have the hex tool!

TheSebringOne

08-08-2010, 10:55 PM

152,000 km or approximately 94-95,000 m. Its on a later thread! :)

mart155

09-09-2010, 03:58 PM

Just out of interest, what would happen if you just reinstalled the failed pulley without the rubber bit in. Anyone know?

Nick Graves

09-09-2010, 04:54 PM

Might get you home, but it's there to dampen torsional vibrations on the NSX's unbalanced 90° crank.

Not recommended as a longer-term solution; kncakered bearings or a broken crank aren't funny.

09-09-2010, 05:53 PM

There are some GT ROM and some older SC pulleys that were designed without the damper.

I would not run it without it.

Nick Graves

09-09-2010, 06:43 PM

A Supercharger pulley's got a pretty big damper on it anyway.

Kaz-kzukNA1

09-09-2010, 07:37 PM

Silver Surfer

10-09-2010, 06:49 PM

Is it worth as a group buy from NSXprime??

http://www.nsxprime.com/forums/showthread.php?t=132194

The HB cost $585...is that too much compare to HUK?

SS

NSXGB

10-09-2010, 07:19 PM

SS... FYI the OEM HB from the US is around $230.

Silver Surfer

10-09-2010, 07:55 PM

Does more power/HP require a different HB??

SS

10-09-2010, 07:59 PM

Does more power/HP require a different HB??

SS

Not relly if you read through the evidence.

Nick Graves

10-09-2010, 08:02 PM

For many production cars, as Nick mentioned, this weight at the crank pulley is to dampen the torsional vibration.
However, on our NSX, the main purpose is for the protection of timing belt.

On the engine dyno, there is a resonance frequency at a certain rpm that could shorten the life of timing belt and in order to shift this frequency out of the useable rpm, our NSX must use this weight at the crank pulley.

I know there are several aftermarket ones available but never used them on the dyno with endurance mode so can’t comment on them.

Kaz

Thanks for correcting that, Kaz. It's actually the sort of information I find fascinating.

Makes me wonder HTH they worked out it needed that? Apart from wrecked prototypes and clever stress sensors, of course.

markc

12-09-2010, 10:34 AM

For many production cars, as Nick mentioned, this weight at the crank pulley is to dampen the torsional vibration.
However, on our NSX, the main purpose is for the protection of timing belt.

On the engine dyno, there is a resonance frequency at a certain rpm that could shorten the life of timing belt and in order to shift this frequency out of the useable rpm, our NSX must use this weight at the crank pulley.

I know there are several aftermarket ones available but never used them on the dyno with endurance mode so can’t comment on them.

Kaz

So if you're prepared to change the timing belt more often, say every 4yrs(?), you can forgo the nasty, heavy stock harmonic balancer for a nice light, regular crank pulley?

Just an idea for anyone tempted to upgrade to a lighter flywheel/clutch assembly in the name of throttle response and annoyed at the ugly lump of iron at the other end of the crankshaft.

Cheers

Mark

NSXGB

12-09-2010, 11:27 AM

Good point, maybe coupled with a stronger TB?
Trouble is you are venturing into unknown territory...

Would throttle response be noticeably different?

markc

12-09-2010, 12:12 PM

Good point, maybe coupled with a stronger TB?
Trouble is you are venturing into unknown territory...

Would throttle response be noticeably different?

I really meant when not under load i.e. blipping the throttle in neutral while at rest. You'd notice the revs rise an fall more quickly. When driving you would notice it when changing gear with greater control for heal and toe shifting :)

Cheers

Mark